1. Field of the Invention
The present invention relates to a method and/or apparatus for improving a navigation performance of a robot, and more particularly, to a sensor which is used to detect obstacles.
2. Description of the Related Art
Various kinds of methods are used for robot navigation.
Map-based navigation methods, such as a vector field histogram (VFH) (“Real-time obstacle avoidance for fast mobile robots in cluttered environments”, IEEE International Conference on Robotics and Automation, vol. 1, pp. 572-577, 1990) and U.S. Pat. No. 5,006,988 entitled “Obstacle avoiding navigation system”, construct the presence and absence of obstacles using histogram according to angles. Since information on real distance to the obstacles is not contained, it is possible to avoid the obstacle, however, hard to navigate the robot to move close to the obstacles.
Sensor-based navigation methods, such as Bug, Bug2, DistBug and VisBug, have disadvantages in that they cannot detect obstacles that are disposed in directions in which sensors are not installed. In other words, in order to correctly detect positions of the obstacles, a large number of sensors are required.
In order to solve these problems, rotary sensor based navigation methods, such as U.S. Pat. No. 5,309,212 entitled “Scanning rangefinder with range to frequency conversion” and Japanese Patent No. 2002-215238 entitled “Obstacle detecting sensor of automatic guided vehicle”, rotate sensors or additional devices (mirrors, prisms, etc.), which are attached to the sensors, in order to decrease the number of sensors, thus obtaining the same effect as the case when a large number of sensors are installed. However, due to the rotation of the sensors, delay time occurs and it is necessary to design a complex apparatus such as mirror/prism rotating devices.